#include <iostream>

using namespace std;

struct A
{
	int i = 0;
	auto operator<=>(const A&) const = default;
};

struct B
{
	A a1;
	A a2;
	auto operator<=>(const B&) const = default;
};

int main()
{
	B b1 = { {1}, {2} };
	B b2 = { {3}, {4} };
	if (b1 < b2)
	{
		cout << "b1 < b2" << endl;
	}

	return 0;
}